Virulent language castigating immigration and Islam is creeping from extremist fringe groups on social media and the dark web into politics, and getting new visibility in the final thrust of campaigning for this month’s European Parliament elections . It’s raising concerns that ideas that once shocked are becoming commonplace.

Phrases like “massive invasion,” and “substitution” by migrants are increasingly part of the political lexicon as far-right populist parties , expected to make significant inroads in the May 23-26 voting across the EU, promote their anti-immigration themes.

A forthcoming study shared with The Associated Press shows a dramatic rise in recent years of two in particular: “the great replacement,” which asserts that European populations are being supplanted by Muslim immigrants as part of a global plot, and its corollary, “remigration,” the chilling notion of returning immigrants to their native lands in what amounts to a soft-style ethnic cleansing.

The terms remain verboten for mainstream politicians on a continent scarred by the Holocaust — and that has worked for half a century to ensure such a horror could never happen again, through an unprecedented project to break down borders and overcome age-old ethnic conflicts called the European Union.

The extreme language gained renewed stigma with the March slayings of 51 Muslim worshippers in Christchurch, New Zealand, by an Australian white supremacist who entitled his manifesto, “The Great Replacement.”

It has also gained new attention, with the man who coined the term nearly a decade ago, Renaud Camus, now himself a candidate for Europe’s legislature.

From the tower of his 14th-century chateau in Gascony, in southwest France, Camus can see the distant Pyrenees Mountains bordering Spain, and the rolling French countryside dotted with church steeples that he fears could be replaced with minarets.

In his vast library, Camus has for years been working in near-invisibility. But increasingly, he’s having an impact beyond his castle walls.

An investigation of social media usage of the terms “the great replacement” and “remigration” by the Institute for Strategic Dialogue showed a sharp rise in the volume of tweets referring to them in the seven years between April 1, 2012 and April 1, 2019.

The term “the great replacement” spiked after the Christchurch attack, but even a month before the bloodbath, ISD data revealed 24,821 mentions — up from 3,431 in April 2012.

Over half of the 750,000 tweets with an identifiable location came from France.

Camus was found to be the top “influencer,” with the highest number of mentions or retweets of the terms. President Donald Trump was ninth in a list of 10 top influencers. Although Trump has never retweeted the phrase or related hashtags, his unyielding attacks on immigration and provocative language have been welcomed by nationalists who champion the ideas.

Camus, 72, said he decided to run for a seat on the European Parliament, because “something enormous is happening that was never named.”

Stressing that he opposes violence, Camus boasted in an interview that his tiny party, The Clear Line, dares to put names on what others only talk about.

“We need remigration,” he said. “As long as (politicians) don’t talk about remigration, they are accepting the status quo ... which is occupation, colonization, Islamization,”— a “genocide by substitution.”

While Camus remains marginal, his ideas are increasingly shared in corridors of power.

Germany’s far-right Alternative for Germany party — the largest opposition group in the country’s federal parliament — has unblinkingly crossed an unspoken red line.

“Germany and Europe must put in place remigration programs on the largest possible scale,” its party platform says.

The leader of Austria’s far-right Freedom Party, Heinz-Christian Strache — also the country’s vice chancellor — created an uproar last month by saying his party was fighting against “replacement of the native population.”

“We’ve seen a shift of ... what is considered acceptable discourse in the last two years,” said Julia Ebner , one of two authors of the Institute for Strategic Dialogue study.

Over the past seven years, she said, there has been “a strong increase on mainstreaming” Camus’ theories “and a lot of this has happened through political actors amplifying some of the words.”

Virulent language against immigration or Islam is not new in France.

In 1991, center-right former President Valery Giscard d’Estaing evoked an “invasion” of immigrants. Another former president, conservative Nicolas Sarkozy, all but stepped into far-right territory with his creation of a ministry of national identity during his 2007-2012 term. His denunciation of “massive immigration” was a drum beat of his presidency.

But most politicians in France — careful of language that echoes the country’s Nazi collaborationist past — still veer away from direct mention of “the great replacement” and “remigration.”

National Rally leader Marine Le Pen, like numerous other populists, uses other words to describe the same concept, as does her party’s top candidate, Jordan Bardella, 23, from a Paris suburb known for a high population of immigrants.

Bardella dismissed the notion as a “slogan for intellectuals” when asked recently on BFMTV if he subscribes to the idea of a “great replacement.” But he went on to claim that some French neighborhoods have been subjected to a “substitution of population,” language also used by Le Pen.

The French far-right leader recently went a step further, saying the wave of Muslim migration is “desired, organized and financed” by the European Union — echoing claims by the ultra-right that it is part of a plot by Europe’s ruling elite.

Such remarks are “typical of the rhetorical strategy” of the far right, said Emmanuelle Reungoat, who has researched the far right in Europe.

“They flirt with taboo words or what is not ... politically correct,” she said. “The idea is to gain visibility.”

That worries some experts.

Jean-Yves Camus, a top expert on far-right extremism, says such terms are worrisome because they “give intellectual ammunition to the extreme right, though not necessarily arguments to turn to terrorism.”

Another leading expert, however, warned they can at times lead to violence.

“It’s perhaps time to repeat that this game (of playing with words) produces massacres,” Nicolas Lebourg, a historian at the University of Montpellier, told the Le Monde newspaper.

___

Associated Press writers Lori Hinnant in Paris and Frank Jordans in Berlin contributed to this report.